Changes in Oil Palm Frond Fiber Morphology, Cellulose Crystallinity and Chemical Functional Groups during Cellulose Extraction Phases

Oil palm fronds (OPF) are agricultural by product and economical natural fibers resources. Cellulose is the main constituent in plant cell wall and because of its mechanical properties, cellulose fibers are potential to be utilized as reinforcement in composite product. The strength of cellulose is affected by its crystalline structure. To extract cellulose from natural fibers, lignin and hemicellulose have to be separated for instance by pulping and bleaching process. The main goal of this study was to observe changes in the OPF fibers morphology, cellulose crystallinity and chemical functional groups during cellulose extraction phases. Soda pulp of OPF was bleached using hydrogen peroxide. Subsequently, the bleached pulp was reacted with potassium hydroxide to eliminate hemicellulose. Afterward, further hydrogen peroxide bleaching was conducted to extract the cellulose. Surface morphological study using SEM revealed that there was a reduction in fiber diameter during cellulose extraction. Cellulose crystallinity and chemical functional groups at each phase of cellulose extraction were slightly different as demonstrated by XRD and FTIR analysis. Keywords: oil palm frond soda pulp, cellulose extraction, fiber morphology, cellulose crystallinit

Analisa Sifat Mekanik pada Bahan Anti Peluru dari Adisi Berpenguat Serat Panjang Tandan Kosong Kelapa Sawit (TKKS)

Kelapa sawit merupakan salah satu hasil perkebunan di Indonesia yang perkembangannya meningkat setiap tahun. TKKS merupakan limbah dari pabrik sawit yang pemanfaatannya belum optimal sehingga akan menjadi limbah padat. Penggunaan serat TKKS pada biokomposit adalah upaya reduksi dan pemanfaatan limbah TKKS yang melimpah. Tujuan dari penelitian ini adalah untuk mendapatkan biokomposit dengan adisi serat panjang TKKS ter-modifikasi untuk aplikasi bahan anti peluru dan mengetahui sifat mekanisnya. Sifat mekanik pada biokomposit yang diperoleh pada penelitian ini memiliki sifat mekanik yang baik untuk aplikasi bahan anti peluru, dimana biokomposit tersebut lentur dan mampu meredam gaya dan energi yang diberikan oleh peluru. Sampel terbaik berada pada biokomposit yang mengandung konsentrasi serat sebesar 18% dengan polimer epox

Sifat fisik, mekanik dan akustik papan partikel berbahan dasar batang jagung (Zea mays L.) [Physical, mechanical and acoustical characteristics of particleboard made from corn stalk (Zea mays L.)]

Corn stalk is considered as agricultural by-products that is abundance and easy to obtain in Indonesia. Corn stalk is an agricultural by-product that highly potential to be exploited as raw material for particleboard production. The research was aimed to evaluate the use of corn stalk in the production of particleboard especially for its acoustics and physical properties. Targeted board density was 0.5 g/cm3and 0.7 g/cm3. The Adhesive used in the board production were urea formaldehyde 10%, phenol formaldehyde 10% and isocyanate (pMDI) 10% based on their solid content. Board dimension was 35 x 35 x 1 cm. The pressure used was 25 kgf/cm2, temperature of 130℃ and 150℃ for 10 minutes. After production, boards were conditioned at room temperature for 7 days prior to testing. The standard for physical and mechanical properties JIS A 5908-2003, Acoustic properties testing was according to JIS A 1405-1963. The result shows that particleboard with isocyanate adhesive both with low and medium density had the best result. Acoustic testing shows that the highest sound absorption coefficient was given by particleboard with isocyanate at frequency 1500 Hz

NANOHIDROGEL TAPIOKA MENGGUNAKAN EPIKLOROHIDRIN SEBAGAI AGEN PENGIKAT SILANG

Natural polymer-based nanohydrogel, like starches, promises superior properties such as more eco-friendly, and cheaper prices because their raw materials are available naturally in abundant quantities compared to synthetic polymers. To obtain synthetic approaching characteristics, natural polymers need to be modified to improve their mechanical stability. Research has been conducted to develop the hydrogel prepared from acid hydrolysed starch for 2 hours and 24 hours. The process of synthesising nanoparticles from hydrolyzed tapioca starch was done through the precipitation of ethanol. Synthesis of nanohydrogel was conducted by crosslinking methods using epichlorohydrin (Ech.) 5, 10, and 20%. Result showed that the particle size of tapioca nanohydrogel ranging from 14.97 – 492.7 nm. The most optimum treatment was nanohidrogel resulted from 2 hours hydrolyzed tapioca with 5% Ech. concentration, resulting swelling power, gel fraction, and texture of  357.02 %, 77,71 %, and 5.61 mJ, respectively. Nanohydrogel is promising material as carrier matrix for agrochemical as well as fertilizer. Keywords : epichlorohydrin, nanohydrogel, tapioc

KOMPOSIT PLASTIK SEBAGAI BAHAN ALTERNATIF KAPAL PENANGKAP IKAN

Armada kapal penangkapan ikan saat ini masih didominasi oleh kapal tradisional. Kapal ikan tradisional pada umumnya terbuat dari bahan kayu. Menimbang dari kondisi alam Indonesia yang sebagian besar adalah perairan laut, maka aktivitas penangkapan ikan sangat tinggi. Kebutuhan akan kapal penangkapan ikan yang meningkat turut meningkatkan permintaan kayu. Pada proses pembuatan kapal penangkap ikan tradisional, nelayan menghadapi berbagai permasalahan, di antaranya harga kayu cukup mahal karena ketersediaannya menurun. Kualitas kayu yang menurun juga mempengaruhi ketahanan dan keawetan kapal berbahan kayu. Oleh karena itu dibutuhkan sebuah bahan pengganti yang digunakan dalam pembuatan kapal penangkap ikan tradisional, agar kualitas kapal yang dibuat memiliki mutu baik dan nelayan mendapatkan hasil tangkapan yang berlimpah ketika melaut. Bahan alternatif pengganti kayu, dapat berupa bahan yang mengandung lignoselulosa, yang kemudian dikombinasikan dengan bahan plastik untuk mendapatkan material dengan sifat yang lebih baik. Studi pustaka ini membahas bahan alternatif pembuatan kapal ikan yang memungkinkan sebagai pengganti kayu, yang berupa komposit dari bahan plastik dan bahan yang mengandung lignoselulosa, terutama komposit polipropilena dengan pengisi jerami padi atau serat kelapa. Kata kunci:  jerami padi, kapal penangkap ikan, komposit lignoselulosa-plastik, polipropilena, serat kelap

Production of binderless fiberboards from Calophyllum inophyllum twin-screw extrusion cakes through thermopressing

Vegetable oil from Calophyllum inophyllum kernels appears as a promising raw material for biodiesel production in Indonesia. For this, the oil must first be extracted and this is the twin-screw extrusion technology that has been used in that case to conduct such extraction. A two-step process was developed consisting in a mechanical pressing and then in the aqueous extraction of residual oil in the press cake. And, it should be noted that a fibrous residue (i.e. sunflower hull) was added in the second twin-screw reactor to facilitate the liquid/solid separation during the aqueous extraction stage. In the best condition tested, 63% of the oil was extracted. In addition, depending on the extrusion conditions used, residual oil content in the final cake varied from 16.7 to 19.1% of its dry matter instead of 74.0% inside the starting material (i.e. the kernel). In this study, the use of the final cakes as sources for fiberboard manufacture through thermopressing was investigated. These cakes can be considered as natural composites with lignocellulosic fibers from the fibrous residue and proteins from the Calophyllum inophyllum kernel breakdown process acting respectively as reinforcing fillers and a natural binder [1-2]. Cohesive self-bonded boards were thus obtained through thermopressing using the next molding conditions: 200 °C temperature, 20 MPa pressure and 300 s molding time. For the three cakes tested, part of their residual oil was expressed through the sidewall vents of the mold during molding, which was due to the applied pressure, and this contributed to the increase in the total vegetable oil recovery. In addition, the more the residual oil content in the cake, the more the oil expressed. However, oil expression during molding reduced the mechanical resistance of fiberboards, due to defects appearing within the material as the oil escaped. This contributed to a slight increase in the bending properties (from 12.1 to 15.4 MPa for flexural strength at break and from 1.9 to 2.0 GPa for elastic modulus) with the cake’s residual oil content decrease (from 19.1 to 16.7%). A significant improvement in the molding process consisted in conducting the cake’s deoiling prior thermopressing using a Soxhlet extraction apparatus and cyclohexane as extracting solvent. From this, the properties of the corresponding board (4.3 mm thickness and 1185 kg/m3 density) were much improved: 79° Shore D surface hardness (instead of 70° without deoiling), 23.7 MPa flexural strength at break and 3.1 GPa elastic modulus. In parallel, thickness swelling after 24 h immersion in water was 43.9% and it has decreased up to 27.6% after the board’s heat treatment (200 °C during 10 min). This optimal fiberboard complied with the French standard NF EN 312 (standard dedicated to the specifications for particleboards), type P7 (i.e. load bearing boards for use under high stress and in wet conditions) for flexural properties (recommendations of 21 MPa and 3.1 GPa for flexural strength at break and elastic modulus, respectively, for boards with a 4 to 6 mm thickness). However, thickness swelling after immersion in water will need to be significantly reduced to achieve the 10% recommended standard value

EFEK PENAMBAHAN ASAM FENILFOSPONAT-SENG, TALK DAN TRIASETIN TERHADAP LAJU KRISTALISASI POLIASAM LAKTAT

Dalam aplikasi industri, salah satu kekurangan poli asam laktat (PLA) adalah kristalisasi yang lambat, sehingga meneyebabkan waktu yang lebih lama untuk mengolah PLA dibandingkan dengan polimer konvensional seperti polipropilen. Penelitian ini mengevaluasi pengaruh penambahan pengisi atau aditif terhadap laju kristalisasi PLA. PLA dilarutkan dalam diklorometana (DCM) dan dicampur dengan nucleating agent (seng asam fenilfosfonat atau talk) atau pelunak (triasetin) pada konsentrasi yang berbeda diikuti dengan pengeringan pada suhu kamar selama 24 jam dan  pengeringan oven selama 2 jam pada suhu 80 °C. Campuran kering PLA  ditempa panas pada 180 °C selama 10 menit. Differential Scanning Calorimetry (DSC) dilakukan untuk mengevaluasi tingkat kristalisasi. Hasil studi menunjukkan bahwa penambahan pengisi atau aditif mempercepat proses kristalisasi PLA. Asam seng fenilfosponat (PPA-Zn) adalah pengisi yang paling efektif untuk mempercepat laju kristalisasi PLA

KARAKTERISTIK SIFAT MEKANIK BIOPLASTIK PATI SINGKONG/PVA DENGAN PENAMBAHAN PULP TANDAN KOSONG KELAPA SAWIT DAN ASAM SITRAT TERAKTIVASI

Bioplastik pati singkong telah banyak dilirik sebagai alternatif pengganti plastik non-degradasi. Namun sifat mekanik yang rendah mengharuskan dilakukannya penambahan bahan adiktif seperti polivinil alkohol (PVA) dan dimodifikasi dengan penambahan pulp tandan kosong kelapa sawit (TKKS) maupun dengan asam sitrat teraktivasi (AS). Komposisi optimum bioplastik terplastisasi/ PVA  yang didapat yaitu sebanyak 5,5 gram pati singkong, 0,275 gram gliserol, dan 5,5 gram PVA. Pada pembuatannya pati singkong dengan bahan aditif lainnya dicampur pada suhu 75 oC dan dituangkan pada cetakkan, kemudian dikeringan pada suhu ruang. Nilai kuat tarik dan presentase elongasi dilihat sebagai indikasi sifat mekanik. Pada penelitian ini dihasilkan penambahan komposisi 0,055 gram TKKS menghasilkan kuat tarik 14,248 N/mm2 dan presentase elongasi sebesar 29,596% dibandingkan dengan penambahan AS teraktivasi sebanyak 0,825 gram dengan nilai kuat tarik 14,512 N/mm2 dan presentase elongasi sebesar 16,932%. Gugus fungsi O–H, C–H, C=O, dan C–O mengindikasikan interaksi komposit bioplastik yang terkonfirmasi menggunakan spektroskopi FTIR. Menurut tes differential scanning colorimetry (DSC) ditunjukkan adanya puncak endotermik yang merupakan kondisi peleburan dari pengaruh interaksi komposisi dalam bioplastik selama proses pemanasan. Dari hasil penelitian membuktikan bahwa bioplastik terplastisasi/ PVA dengan penambahan TKKS mampu meningkatkan sifat mekanik dan dapat digunakan sebagai acuan pembuatan bioplastik, khususnya sebagai kemasan

Eco-friendly Board from Oil Palm Frond and Citric Acid

The utilization of oil palm fronds as composite board raw material has developed due to the declining wood supply. Currently, citric acid is used as natural adhesive on the wood-based moldings to reduce the use formaldehyde-based resin. Citric acid has carboxylic acid functional group that can react with hydroxyl functional group from cellulose by esterification reaction. This paper explain the production of board from oil palm frond and citric acid, then elaborate their physical and mechanical properties.  Oil palm fronds were processed with ring flaker to produce particles with 1 ~ 5 cm length. The particles were dried until the moisture content reached 6%. Citric acid solution was obtained by stirring 700 g citric acid in 1000 ml water.  Citric acid solution were sprayed onto particles. The weight of citric acid were 10%, 15% and 20% based on oil palm fronds’ dry weight. Boards were produced with density target of 0.6 g/cm3 and pressure at 1N/mm2 for 10 min. The hot pressing temperatures were varied at 140ºC, 160ºC, 180ºC, and 200ºC. Physical and mechanical test were performed according to JIS A 5908-2003. The MOR, MOE, IB and SW values of boards with 15 wt% citric acid content and pressed at 200oC were 5.85 N/mm2, 1067.03  N/mm2, 0.26 N/mm2 and 88.80 N respectively. The optimum condition for board production obtained upon citric acid content and pressing temperature in a range of 15% ~ 20% and 180ºC ~ 200ºC, respectively

Karakterisasi Nanokristal Selulosa Dari Eceng Gondok Dan Pengaruhnya Terhadap Sifat Mekanik Dan Biodegradabilitas Bioplastik Pati

Plastik yang terbuat dari minyak bumi menjadi masalah bagi lingkungan karena sulit terurai oleh mikroorganisme. Pada tahun 2016, jumlah sampah plastik mencapai 242 juta ton di seluruh dunia. Untuk mengatasi hal tersebut, bioplastik pati yang bersifat biodegradable dapat menjadi alternatif pengganti plastik. Namun, sifat mekanik bioplastik pati lebih rendah dibandingkan plastik sehingga nanokristal selulosa (NKS) ditambahkan untuk meningkatkan sifat mekaniknya. NKS berperan sebagai agen penguat karena kompatibel serta memiliki sifat mekanik dan kristalinitas yang tinggi. Pada penelitian ini, NKS diisolasi dari eceng gondok yang merupakan gulma yang memiliki kandungan selulosa mencapai 60%. Kemudian, NKS dengan konsentrasi 0;2;4;6;8;10% ditambahkan ke bioplastik pati yang bertujuan untuk mengetahui pengaruhnya terhadap terhadap kuat tarik, elongasi, dan biodegradabilitas. Hasil karakterisasi NKS menunjukkan bahwa terdapat perubahan gugus fungsi, peningkatan indeks kistalinitas, dan tidak terdapat struktur fibril akibat perlakuan kimia. Pada kuat tarik bioplastik, terdapat perbedaan yang nyata antara perlakuan kontrol dan perlakuan penambahan NKS 2% serta pada elongasi tidak terdapat perbedaan yang nyata. Selama uji biodegradbilitas, bioplastik mengalami perubahan fisik dan massa yang fluktuatif. Penurunan massa terbesar terjadi pada perlakuan NKS 6% pada hari ke-10